The protein RDA of 0.8 grams per kilogram of body weight has been the reference number for decades. It shows up on nutrition labels, in dietary guidelines, and in most online protein calculators. A 2026 review in Frontiers in Nutrition argues that number was never built for the question people actually care about as they age.
The RDA was set using nitrogen balance studies conducted primarily in young, healthy adults. It represents the minimum intake needed to avoid deficiency in most of the population. It was never designed to answer how much protein a person needs to preserve muscle, strength, and independence over decades.
Why Older Adults May Need More
As people age, skeletal muscle becomes less responsive to the normal signals that trigger muscle protein synthesis, a phenomenon researchers call anabolic resistance in older muscle. A dose of protein that would stimulate muscle building in a 30-year-old may produce a smaller response in a 70-year-old, even at an identical amount.
This isn’t a switch that flips at a specific birthday. It’s a gradual shift that tends to become more noticeable from the 50s onward and more pronounced in the 70s and beyond. Age here is better thought of as a continuum than a hard cutoff.
Several expert groups have argued that older adults need meaningfully more protein than the RDA to offset this reduced responsiveness. A review of protein recommendations for older people puts most targets in the range of 1.0 to 1.5 grams per kilogram per day, with some intervention studies using up to 1.6 to 2.0 grams per kilogram, particularly when combined with resistance training.
What the Evidence Actually Supports
The strongest data comes from studies combining higher protein intake with resistance exercise. A Journals of Gerontology review of feeding trials found reasonably consistent evidence that intakes above the RDA, paired with training, help preserve lean mass and improve measures like grip strength, chair-rise time, and gait speed.
The evidence is weaker for protein alone, without a training stimulus. Some observational studies show associations between higher protein intake and better physical function, but observational data can’t establish cause and effect. Most randomized trials in this area are short, often a few months, which makes it hard to know what happens over years or decades.
There’s also a gap in the research: most studies focus on adults in their 60s and 70s. Data on adults 85 and older, the fastest-growing segment of the older population, is much thinner. Recommendations for that group are closer to extrapolation than direct evidence.
Not every expert agrees the RDA needs revising. A minority position holds that the current RDA is adequate for healthy, non-exercising adults, and that higher targets are driven more by studies in active or clinical populations than by data representative of the general aging population. That disagreement hasn’t been fully resolved, though it reflects a minority view within the field.
Distribution May Matter as Much as the Total
A number of researchers argue that how protein is spread across the day matters as much as the daily total. Because of anabolic resistance, a single large dose late in the day may be less effective than the same total split across three or four meals, each containing roughly 30 to 40 grams and enough leucine, an amino acid concentrated in animal protein, to meaningfully trigger muscle protein synthesis at the meal level.
This is a more mechanistic argument than a settled clinical outcome. It’s biologically plausible and consistent with lab studies, but there isn’t yet strong long-term outcome data comparing meal-distribution strategies head to head.
What About Kidney Health?
Concerns about protein and kidney damage come up often, but the evidence applies mainly to people with pre-existing kidney disease. In healthy, community-dwelling older adults, higher protein intake within the ranges above hasn’t been shown to harm kidney function. Anyone with existing kidney disease should talk to a doctor before increasing intake significantly.
The Reasonable Take
The RDA is a floor, not a target. For most healthy older adults, especially those doing any form of resistance training, aiming meaningfully above 0.8 grams per kilogram, somewhere in the 1.0 to 1.5 gram range, is well supported by current evidence. Going substantially higher shows diminishing returns in most studies.
What isn’t settled is the exact number for any given individual, how much meal timing matters in practice, and what applies specifically to the oldest adults. Treat specific targets as a reasonable range to work within, not a precise prescription.
Related Links
- Scientists say most people need more protein
- Unresolved questions in dietary protein requirements
- Protein recommendations for older people reviewed
- Dietary protein and skeletal muscle in aging
- Protein source and muscle health review
- Optimal protein intake for ageing adults
- Exercise, nutrition, and healthy aging